if ($('#check_id').is(":checked"))
{
// it is checked
}
$('#checkbox_id:checked').val();
//if checkbox is selected than gets its value
console.log($('input[name="locationthemes"]:checked').serialize());
//or
$('input[name="locationthemes"]:checked').each(function() {
console.log(this.value);
});
$('input[name="checkboxGroup"]:checked'); // returns checked input objects
$("#check").change(function () {
if (this.checked) {
//I am checked
name_val = $('#name').val();
$('#player').val(name_val);
} else {
//I'm not checked
$('#player').val('');
}
});